We can see many molecules flying in the air when a sunbeam penetrated the dark room.

In other words I mean in the desert you have the carbon granules which would collect moisture on top of them.

Similarly, if it is dusty or there are a lot of other larger particles in the air, this will filter out larger wavelengths, resulting in a red sky and red sun.

The lights are caused by a flow of electrically charged particles to and from one of Saturn's moons.

It is currently cheaper, an Indian businessman says ruefully, to export plastic granules to China and then import them again in bucket-form, than it is to make buckets in India.